In 1970, Charlie Watkins (of WEM PA fame) introduced Dudderidge to Led Zeppelin, beginning not only Dudderidge's first live sound engineer assignment, but also the notable position of Led Zeppelin's first dedicated live sound engineer (and "WEM expert"). This job lasted from March to May 1970, encompassing tour dates in both Europe and the U.S.[3]

While house engineer for the Implosion concerts at the Roadhouse in London, Dudderidge worked with Hiwatt to develop professional sound reinforcement systems.[4] He then partnered with Paul Dobson and Graham Blyth to form his first company, RSD, building custom PA systems for Roy Wood's Wizzard and Steve Harley & Cockney Rebel amongst others, with custom-built mixing consoles derived from a Bill Kelsey original design.[5] During the '70s, Blyth and Dudderidge owned Europa Concert Systems, a live sound company that catered to American bands touring Europe.[6]

In 1973, Dudderidge and Blyth left RSD to form Soundcraft Electronics, Ltd.,[7] the company specializing in live sound and recording mixing consoles. Dudderidge's involvement with this company also led to his working with notable pro audio industry figures Betty Bennett (CEO of Apogee Electronics), Wayne Freeman (of Trident USA, Fairlight, Amek, Otari, and most notably Marshall Electronics), and Shane Morris (designer of the ATI Paragon monitor console and later of PRS Guitars).[8][9] 15 years later, in 1988, Soundcraft, firmly established as a leading console brand, was sold to Harman International Industries. For the next year, Dudderidge continued working for Soundcraft as Managing Director.

Dudderidge left Soundcraft in early 1989 and acquired the assets of Rupert Neve's company, Focusrite Ltd., thus inheriting the Focusrite range designed prior to 1989.[10] A new company, Focusrite Audio Engineering Ltd. was formed to continue to develop and manufacture Focusrite products. Dudderidge is currently Chairman of Focusrite Audio Engineering, Ltd. Focusrite acquired the assets of Novation Electronic Music Systems. in 2004 and the Novation brand became integrated into the business. Focusrite established Focusrite Novation Inc. to represent its interests in the United States and manage marketing and Tier One reseller relationships. FNI is based in Los Angeles, CA. Focusrite UK also distributes third-party brands from the Stanton Group, notably KRK Loudspeakers and also Ableton Live software.

Phil Dudderidge was born in 1949, the second son and fourth child of John Dudderidge OBE and Dr. Evelyn Dudderidge (née Hughes). He married Jennifer "Jenny" Hayes in 1973. The couple produced five sons and a daughter: Dr. Tim Dudderidge; Tom Dudderidge, founder of Disruptive Ltd. (Gear4); Jamie Dudderidge, founder of Commute(Sydney, Aus.); Simon Dudderidge Alternative Networks; Jo Dudderidge, singer, songwriter and multi-instrumentalist with The Travelling Band and Joanna Dudderidge, photographer.